JP5897255B2 - Optical element and manufacturing method thereof - Google Patents

Description

  The present invention relates to an optical element and a manufacturing method thereof. In particular, the present invention relates to an optical element including a polymer photonic crystal and a manufacturing method thereof.

  A photonic crystal is a structure in which substances with different refractive indexes are periodically arranged in units of the order of the wavelength of light, and a band that completely blocks light of a specific wavelength due to the refractive index periodic structure. It is known that a gap (photonic band gap) occurs. It is known that the transmittance of light of a specific wavelength can be controlled by adjusting such a refractive index periodic structure.

  In addition, a one-dimensional photonic crystal, that is, a multilayer film of substances having different refractive indexes, can be used as a notch filter that reflects a specific wavelength according to the period of the multilayer structure and does not transmit it. Such a multilayer film is conventionally produced by a vapor deposition method or a sputtering method and widely used.

  In the case of vapor deposition and sputtering, it is necessary to use a large vacuum device and the work is complicated. On the other hand, as a method for easily producing a multilayer film, polymer materials having different refractive indexes are applied by spin coating. A method of stacking is known (for example, see Patent Document 1 below). However, in the manufacturing method of Patent Document 1, it is necessary to perform spin coating many times, and it cannot be said that the method is sufficiently simple.

  In contrast to the photonic crystal produced by the top-down method, a photonic crystal having a microphase separation structure formed by self-organization of a block copolymer as a refractive index periodic structure is known in recent years. (For example, refer to Patent Document 2 below). In this case, the self-organization of the block copolymer is used compared to the case where the dielectric multilayer film is formed by top-down processing that requires the use of a large apparatus (eg, vapor deposition apparatus, pattern exposure apparatus, sputtering apparatus). By doing so, a photonic crystal can be manufactured at a very low cost.

  However, in order to improve the optical characteristics (for example, transmission characteristics) of the optical element, it is indispensable to control the orientation of the microdomains in the microphase separation structure, but many of the conventional microphase separation structures are polycrystalline. The refractive index periodic structure is non-oriented. In addition, since the photonic crystal is in the form of a gel containing a large amount of solvent, the orientation control of the microdomains may not be easy as in the manufacturing method of Patent Document 2, which has a problem in structural stability.

JP-A-2005-55543 International Publication No. 2008/047514 Pamphlet JP 2008-55579 A

Nature Materials 6, 957-960 (2007) Polymer Journal 37, 12, 900-905 (2005) Macromolecules 32, 3695-3711 (1999). Current Opinion in Colloid & Interface Science 5, 342-350 (2000)

  In recent years, as a multilayer filter for blocking specific wavelengths used in Raman spectroscopes, fluorescence microscopes, etc., a polymer containing lamellar microdomains oriented parallel to the main surface of the crystal in a microphase separation structure The use of photonic crystals has been studied, and it is required to improve the optical characteristics thereof. However, a multilayer filter using a photonic crystal having a microphase separation structure, which has been studied in the past, does not have optical characteristics equivalent to those of a dielectric multilayer filter currently on the market (for example, the above-mentioned For example, it is difficult to use as a filter of a Raman spectroscopic device.

  The present invention is intended to solve the above-described problem, and includes a polymer photonic crystal including lamellar microdomains oriented in a direction substantially parallel to the main surface of the crystal in a microphase separation structure. It is an object of the present invention to provide an optical element capable of improving optical characteristics and a method for manufacturing the same.

  Here, Raman spectroscopic measurement using a dielectric multilayer filter is a measurement method for detecting weak Raman scattered light generated by irradiating a sample with excitation light such as a laser. When detecting Raman scattered light, it is necessary to block the excitation light by a filter. In addition, since the wavelength of the Raman scattered light may be close to the excitation wavelength, it is necessary to selectively block only the excitation light with a filter. Therefore, when polymer photonic crystals containing lamellar microdomains oriented parallel to the main surface of the crystal in the microphase separation structure are used for Raman spectroscopic measurement, it is important that the orientation of the microdomains is high. It becomes.

  When controlling the orientation of lamellar microdomains on the substrate surface, it is considered that lamellar microdomains are easily oriented parallel to the main surface of the substrate without any special treatment on the substrate surface. It tends to be considered that it is easy to control the orientation of the shaped microdomains parallel to the main surface of the crystal. For this reason, there have been few reports on the orientation control method for such lamellar microdomains in recent years. By applying a shear flow field to a solution containing a block copolymer, the microdomains are parallel to the main surface. There are only a few reports on controlling the orientation of the film (for example, see Patent Document 3 and Non-Patent Documents 2 to 4).

  However, in the above Non-Patent Documents 2 to 4, although the influence of the shear rate on the orientation of the microdomain is examined, the periodic structure of the microphase separation structure is not so large that it can be used as a photonic crystal, Further, the orientation is not sufficient for use as a photonic crystal optical element.

  As a result of diligent investigations for solving the above problems, the present inventors have found that in the conventional polymer photonic crystal using the microphase separation structure of the block copolymer, the microdomains are sufficiently short with respect to the main surface of the crystal. It has been found that by including a region which is not oriented in parallel, sufficient optical properties cannot be obtained even when such a polymer photonic crystal is used for Raman spectroscopic measurement or the like.

  That is, the optical element according to the present invention includes a polymer photonic crystal having a first main surface and a second main surface facing each other, and the polymer photonic crystal contains a block copolymer, It has a microphase separation structure including lamellar microdomains, and each of the microdomains is oriented substantially parallel to at least one of the first main surface or the second main surface.

  In the optical element according to the present invention, since the polymer photonic crystal has a microphase separation structure including lamellar microdomains, optical characteristics (for example, transmission characteristics) depending on the orientation state of the microdomains can be exhibited. . In the optical element according to the present invention, each of the lamellar microdomains is oriented substantially parallel to at least one of the first main surface or the second main surface. Thereby, in the optical element according to the present invention, the optical characteristics are improved as compared with the optical element using the conventional photonic crystal including the region in which the microdomain is not oriented substantially parallel to the main surface of the crystal. Can be made.

  The average degree of orientation of the microdomains in a plurality of cross sections substantially perpendicular to at least one of the first main surface or the second main surface is preferably substantially the same. In this case, the optical characteristics can be further improved as compared with a conventional photonic crystal optical element using a block copolymer.

The average orientation degree P of microdomains defined by the following formula (1) is preferably 0.92 or more. In this case, the optical characteristics can be further improved as compared with a conventional photonic crystal optical element using a block copolymer.

(In the formula, μ represents an azimuth angle in small-angle X-ray scattering measurement, and <cos ² μ> is defined by the following formula (2).)

(In the formula, I (μ) represents the scattering intensity at the azimuth angle μ.)

The transmission spectrum of the polymer photonic crystal preferably has a wavelength band in which the gradient G defined by the following formula (3) is less than 2.0% between the stop band and the pass band. In this case, the optical characteristics can be further improved as compared with a conventional photonic crystal optical element using a block copolymer.

(In the formula, λ ₅₀ represents a wavelength (nm) showing a transmittance of 50% in the wavelength band, and λ _B represents a wavelength (nm) at the boundary between the stop band and the wavelength band.)

The weight average molecular weight of the block copolymer is preferably 8.0 × 10 ⁵ (g / mol) or more. In this case, a periodic structure necessary for expressing optical characteristics as a photonic crystal can be obtained more satisfactorily.

  The polymer photonic crystal preferably further contains a polymer compound obtained by polymerizing a composition containing at least one photopolymerizable monomer selected from the group consisting of acrylates and methacrylates.

  The polymer photonic crystal may further contain at least one selected from the group consisting of phthalic acid ester, adipic acid ester, phosphoric acid ester, trimellitic acid ester, citric acid ester, epoxy compound and polyester.

  When controlling the orientation of lamellar microdomains, the present inventor applies a random shear flow field to a solution that becomes a polymer photonic crystal, so that only in a specific uniaxial direction as shown in Patent Document 3 above. It was found that the orientation of the microdomains can be controlled better than when a shear flow field is applied.

  That is, in the method for manufacturing an optical element according to the present invention, a block copolymer, a photopolymerization initiator, and the block copolymer are disposed between the main surface of the first member and the main surface of the second member facing each other. And a photopolymerization initiator in a different direction substantially parallel to at least one of the main surface of the first member and the main surface of the second member with a solution containing a soluble photopolymerizable monomer interposed therebetween. A first step in which one member and a second member are moved relative to the solution, and a random shear flow field is applied to the solution. After the first step, the solution is irradiated with light and photopolymerized. And a second step of polymerizing a photopolymerizable monomer to obtain a polymer photonic crystal in which lamellar microdomains are oriented substantially parallel to at least one of the main surface of the first member and the main surface of the second member. .

  In the present invention, the “random shear flow field” means that the first member and the second member are moved relative to the solution to be substantially parallel to at least one of the main surface of the first member and the main surface of the second member. A shear flow field applied in multiple directions in a plane. The random shear flow field is different from a shear flow field applied only in a specific uniaxial direction or a flow field applied concentrically with reference to a specific uniaxial direction.

  In the method for producing an optical element according to the present invention, in the first step, a block copolymer, a photopolymerization initiator, and a photopolymerizable monomer are disposed between the main surface of the first member and the main surface of the second member that face each other. The first member and the second member are moved relative to the solution in different directions substantially parallel to at least one of the main surface of the first member and the main surface of the second member with a solution containing And applying a random shear flow field to the solution. Accordingly, the orientation of each of the lamellar microdomains in the microphase separation structure is controlled substantially parallel to at least one of the main surface of the first member and the main surface of the second member. In the second step, the photopolymerizable monomer in the solution is polymerized to fix the microphase separation structure while maintaining the orientation state of the microphase separation structure obtained in the first step. Crystals can be obtained. In the method of manufacturing an optical element according to the present invention, each of the microdomains is controlled to be oriented substantially parallel to at least one of the main surface of the first member and the main surface of the second member. Optical characteristics can be improved as compared with a photonic crystal optical element using a conventional block copolymer including a region that is not oriented substantially parallel to the surface.

  In the method for producing an optical element according to the present invention, a random shear flow field is applied to the solution, and the block copolymer is self-organized to form a microphase separation structure. Thereby, compared with the case where a photonic crystal is formed by top-down processing, the manufacturing cost of the photonic crystal can be significantly reduced.

The weight average molecular weight of the block copolymer is preferably 8.0 × 10 ⁵ (g / mol) or more. In this case, a periodic structure necessary for expressing optical characteristics as a photonic crystal can be obtained more satisfactorily.

  The photopolymerizable monomer is preferably at least one selected from the group consisting of acrylates and methacrylates.

  The solution may further contain at least one selected from the group consisting of phthalic acid esters, adipic acid esters, phosphoric acid esters, trimellitic acid esters, citric acid esters, epoxy compounds and polyesters.

  According to the present invention, a polymer photonic crystal including a lamellar microdomain oriented substantially parallel to the main surface of the crystal in a microphase-separated structure is provided, and optical characteristics can be improved as compared with the prior art. Possible optical elements can be provided. In addition, according to the present invention, it is possible to provide a production method capable of producing such an optical element by a simple and inexpensive method. Thereby, an optical element provided with a large-area polymer photonic crystal can be easily manufactured.

It is a perspective view which shows the optical element which concerns on one Embodiment of this invention. It is drawing for demonstrating the relationship between a refractive index periodic structure and the wavelength distribution of a transmission spectrum. It is drawing which shows the transmission spectrum for demonstrating the calculation method of edge steepness. It is drawing which shows the transmission spectrum for demonstrating the calculation method of the symmetry of a peak. It is drawing which shows 1 process of the manufacturing method of the optical element which concerns on one Embodiment of this invention. It is drawing which shows 1 process of the manufacturing method of the optical element which concerns on other one Embodiment of this invention. It is drawing which shows 1 process of the manufacturing method of the optical element which concerns on other one Embodiment of this invention. 2 is a TEM photograph of the polymer photonic crystal film of Example 1. 2 is a TEM photograph of a polymer photonic crystal film of Comparative Example 1. It is drawing which shows the two-dimensional scattering pattern of a polymer photonic crystal film. It is drawing which shows the azimuth angle dependence of the scattering intensity in a polymer photonic crystal film. It is drawing which shows the transmission spectrum of a polymer photonic crystal film.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of an optical element and a manufacturing method thereof according to the invention will be described in detail with reference to the drawings.

(Optical element)
FIG. 1 is a perspective view showing an optical element according to this embodiment. The optical element 1 according to this embodiment is a notch filter, for example. The optical element 1 includes a polymer photonic crystal 3 having a main surface (first main surface) 3a and a main surface (second main surface) 3b facing each other substantially in parallel. The polymer photonic crystal 3 is not particularly limited, but has, for example, a circular film shape.

  The polymer photonic crystal 3 contains a block copolymer (polymer block copolymer). The “block copolymer” is a copolymer in which two or more kinds of polymer chains (segments) are bonded. For example, a first polymer chain having the monomer A as a structural unit and a first polymer chain having the monomer B as a structural unit. Examples thereof include a copolymer in which two polymer chains are bonded to each other at the ends of the polymer chains.

  Examples of the block copolymer include polystyrene-b-poly (methyl methacrylate), polystyrene-b-poly (ethyl methacrylate), polystyrene-b-poly (propyl methacrylate), and polystyrene-b-poly (tert-butyl methacrylate). , Polystyrene-b-poly (n-butyl methacrylate), polystyrene-b-poly (isopropyl methacrylate), polystyrene-b-poly (pentyl methacrylate), polystyrene-b-poly (hexyl methacrylate), polystyrene-b-poly (decyl) Methacrylate), polystyrene-b-poly (dodecyl methacrylate), polystyrene-b-poly (methyl acrylate), polystyrene-b-poly (tert-butyl acrylate), polystyrene-b-poly Tadiene, polystyrene-b-polyisoprene, polystyrene-b-polydimethylsiloxane, polybutadiene-b-polydimethylsiloxane, polyisoprene-b-polydimethylsiloxane, polyvinylpyridine-b-poly (methyl methacrylate), polyvinylpyridine-b- Poly (tert-butyl methacrylate), polyvinylpyridine-b-polybutadiene, polyvinylpyridine-b-isoprene, polybutadiene-b-polyvinylnaphthalene, polyvinylnaphthalene-b-poly (methyl methacrylate), polyvinylnaphthalene-b-poly (tert-butyl) 2-block copolymers such as methacrylate), polystyrene-b-polybutadiene-b-poly (methyl methacrylate), polystyrene-b-polybutadiene-b-poly And ternary block copolymers such as (tert-butyl methacrylate), polystyrene-b-polyisoprene-b-poly (methyl methacrylate), and polystyrene-b-polyisoprene-b-poly (tert-butyl methacrylate). . The block copolymer is not limited to the above as long as the refractive index is different between polymer chains.

The lower limit of the weight average molecular weight (Mw) of the block copolymer is 8.0 × 10 ⁵ (g / mol) from the viewpoint that a periodic structure necessary for expressing optical characteristics as a photonic crystal can be satisfactorily obtained. ) Or more, preferably 9.0 × 10 ⁵ (g / mol) or more, and more preferably 1.0 × 10 ⁶ (g / mol) or more. The upper limit of the weight average molecular weight is preferably 3.0 × 10 ⁶ (g / mol) or less, from the viewpoint of obtaining a more favorable periodic structure necessary for expressing optical characteristics as a photonic crystal. 0.5 × 10 ⁶ (g / mol) or less is more preferable, and 2.0 × 10 ⁶ (g / mol) or less is more preferable. In addition, a weight average molecular weight can be obtained as a weight average molecular weight of polystyrene conversion using gel permeation chromatography (GPC).

  The polymer photonic crystal 3 has a microphase separation structure 5. “Microphase separation structure” refers to an aggregate in which microdomains are periodically arranged. “Microdomain” refers to a phase formed by phase separation of different types of polymer chains of a block copolymer without being mixed with each other. The microphase separation structure 5 is a refractive index periodic structure 7 formed by alternately laminating lamellar microdomains 7a and lamellar microdomains 7b. Each of the microdomains 7a and 7b is oriented substantially parallel to at least one of the principal surface 3a or the principal surface 3b. In the present embodiment, the microdomains 7a and 7b are oriented substantially parallel to the principal surface 3a and the principal surface 3b. Yes. The microdomain 7a includes one polymer chain 9a of the block copolymer as a main component, and the microdomain 7b includes another polymer chain 9b of the block copolymer as a main component. Note that the repetition period of the microdomains 7a and 7b and the arrangement of the polymer chains 9a and 9b are not limited to those shown in FIG.

(Orientation degree of microdomain)
Next, the relationship between the degree of orientation of the microdomains and the optical characteristics will be described with reference to FIG. When light is incident on a refractive index periodic structure (multilayer film structure) in which phases having different refractive indexes are stacked, the center wavelength λ of reflected light and the structural period d are caused by the diffraction phenomenon of the refractive index periodic structure. The following equation (4) known as Bragg's equation holds between:

(Wherein λ represents the center wavelength (nm) of the reflected light, d represents the structural period (nm), n is the refractive index of the microdomain, m is an integer of 1 or more, and θ is the refractive index periodic structure. Indicates the angle of incidence on the body.)

  That is, when white light is incident on the refractive index periodic structure as incident light, it is blocked by the microdomain without passing through the center wavelength λ of the reflected light, that is, by the incident angle θ with respect to the refractive index periodic structure and the structural period d. Wavelength (block wavelength) changes. When the incident angle θ with respect to the refractive index periodic structure is 90 ° (normal incidence, regular reflection), the reflection wavelength becomes maximum. The transmission spectrum basically has a shape in which the reflection spectrum is reversed, and indicates that the wavelength satisfying the above formula (4) is not transmitted.

  A refractive index periodic structure 11a shown in FIG. 2 (a) is formed by laminating flat microdomains having a small distribution of the structural period d and having no bend substantially parallel to each other. When white light is incident on the refractive index periodic structure 11a as the incident light L1, the wavelengths of the reflected light and the transmitted light L2 also have a distribution according to the degree of the distribution of the structural period d. For example, as shown in FIG. 2B, the wavelength distribution of the transmission spectrum of the transmitted light L2 is relatively small.

  On the other hand, the refractive index periodic structure 11b shown in FIG. 2C is formed by stacking bent microdomains as well as flat microdomains without bending. When white light is incident on the refractive index periodic structure 11b as the incident light L1, light is incident on the bent microdomain at various angles. When light is incident on the bent microdomain, the wavelength of the reflected light is shifted to the lower wavelength side, so that the transmission spectrum is shifted to the lower wavelength side, and the wavelength distribution of the reflected light and transmitted light L2 is increased. For example, as shown in FIG. 2 (d), the transmission spectrum of the transmitted light L2 has a large wavelength distribution, the bottom of the low wavelength side is greatly expanded, and the steepness is lowered.

  As described above, the wavelength distribution of the transmission spectrum spreads according to the structural period d and the degree of disorder of the microdomain orientation. Even if the structural period d is uniform, if the refractive index periodic structure includes a bent microdomain with disordered orientation, the transmission spectrum is steep on the high wavelength side but steep on the low wavelength side. Is reduced. However, it is rare that the structural period d is uniform and the microdomain orientation is disturbed in this way, and both the structural period d and the microdomain orientation are often disturbed. Therefore, a filter having poor optical characteristics usually has a transmission spectrum in which the steepness on the low wavelength side and the steepness on the high wavelength side are reduced. When a filter having a transmission spectrum whose sharpness is greatly reduced is used as a notch filter, for example, the wavelength difference between the block wavelength and the transmission wavelength is widened, and the wavelength resolution is significantly reduced.

The average degree of orientation of the microdomains can be evaluated by small angle X-ray scattering measurement. Specifically, the polymer photonic crystal 3 is cut in a direction substantially perpendicular to at least one of the principal surface 3a or the principal surface 3b (thickness direction of the polymer photonic crystal 3), and the two-dimensional scattering pattern of the cross section is reduced to a small angle. Measured by X-ray scattering measurement. Thereby, the azimuth (orientation angle) dependence of the scattering intensity depending on the orientation state of the microdomain can be obtained. Based on the measurement result of the azimuth angle dependence of the scattering intensity, the Hermans orientation degree, which is widely used as a method for evaluating the two-dimensional orientation degree, can be calculated as the average orientation degree P (see, for example, JP-A-2001-91502). ). The average orientation degree P is defined by the following formula (1).

(In the formula, μ represents an azimuth angle in small-angle X-ray scattering measurement, and <cos ² μ> represents a mean square defined by the following formula (2).)

(In the formula, I (μ) represents the scattering intensity at the azimuth angle μ.)

  Here, the azimuth angle μ is set to 0 ° in the direction perpendicular to the main surfaces 3a and 3b. That is, the azimuth angle μ corresponds to an inclination angle with respect to the main surfaces 3a and 3b.

  When the average degree of orientation P is 1, it indicates that a lamellar microphase separation structure is formed in which the microdomains are oriented completely parallel to the main surfaces 3a and 3b in the cross section. On the other hand, when the average orientation degree P is 0, it indicates that the microdomains are not oriented in the cross section.

  The average orientation degree P is preferably 0.92 or more, more preferably 0.95 or more, and still more preferably 0.97 or more. When the average orientation degree P is less than 0.92, there is a tendency that many bent microdomains and defects are included in the microphase-separated structure, so that the steepness of the transmission spectrum is lowered and the optical characteristics (transmission characteristics) are lowered. Tend to.

  Further, from the viewpoint of obtaining a steep transmission spectrum, it is preferable that the orientation degree of the micro domains 7a and 7b is substantially the same in any region from the main surface 3a to the main surface 3b. If the polymer photonic crystal 3 contains a large number of regions where the degree of orientation of the microdomains 7a and 7b is low, the steepness of the transmission spectrum tends to decrease and the wavelength distribution tends to widen. The average orientation degrees P of the microdomains 7a and 7b in a plurality of cross sections substantially perpendicular to at least one of the main surface 3a or the main surface 3b are preferably substantially the same. For example, the randomly selected cross sections are mutually It is preferable to give substantially the same average orientation degree P. “The average orientation degree P is substantially the same” means that the difference in the average orientation degree P between the cross-sections to be compared is within 0 to 0.05, for example, the thickness of the microdomain, the main of the microdomain It means that the angle (parallelism) to the surface 3a or the main surface 3b and the density of the polymer chain are substantially the same between the cross-sections to be compared. When the microdomain includes a region that is not oriented substantially parallel to the main surface of the crystal, for example, including a curved microdomain as shown in FIG. 2C, the selected cross section is substantially the same. Must not.

  The optical characteristics of the polymer photonic crystal 3 can be evaluated by the edge steepness in the transmission spectrum and the symmetry of the peak.

(Edge steepness)
In the transmission spectrum of the polymer photonic crystal 3, for example, a stop band (block wavelength band) appears in a wavelength range of 512 to 515 nm. In this case, the transmission spectrum of the polymer photonic crystal 3 has a slope G (hereinafter referred to as “edge steepness G”) defined by the following formula (3) between the stop band and the pass band: It is preferable to have a wavelength band (transition band) that is less than 0%. The “stop band” means a wavelength band that blocks incident light with respect to a pass band through which incident light passes. The stop band may be either a rising edge or a falling edge.

(In the formula, λ ₅₀ represents a wavelength (nm) showing a transmittance of 50% in the transition band, and λ _B represents a wavelength (nm) at the boundary between the stop band and the transition band.)

  The edge steepness G can be calculated by the following procedure. That is, first, light is incident from the main surface 3a or the main surface 3b of the polymer photonic crystal 3, the transmission spectrum is measured, and the wavelength dependency of the transmittance is measured. The same value can be calculated for the edge steepness G regardless of the transmission spectrum of which the vertical axis is the transmittance or the OD value (the common logarithm of the reciprocal of the transmittance). For example, FIG. 3 is a diagram showing a transmission spectrum for explaining a method of calculating the edge steepness G, where the vertical axis shows a value obtained by dividing the transmittance (%) by 100%, and the horizontal axis shows the wavelength (nm). ).

  Next, the wavelength at the boundary between the stop band and the transition band and the wavelength indicating the transmittance of 50% (the wavelength indicating the vertical axis 0.5 in FIG. 3) are extracted from the transmission spectrum. In FIG. 3, the rising wavelength indicated by the solid line A is the wavelength at the boundary between the stop band and the transition band, and the wavelength indicated by the solid line B is a wavelength indicating a transmittance of 50%. Then, the edge steepness G is calculated from the above equation (3).

Incidentally, for example, in Raman spectroscopy because it may signal is observed in the vicinity of 500 cm ^-1, there is a need to ensure a degree 400 cm ^-1 as a measurement limit of the low frequency side. In the filters for Raman spectrometers currently on the market, 400 cm ⁻¹ is secured as the measurement limit on the low wavenumber side, and the edge steepness is 2.0% or less. Therefore, the edge steepness G of the polymer photonic crystal 3 is preferably less than 2.0%, more preferably less than 1.5%, and more preferably 1.3% from the viewpoint of sufficiently ensuring the measurement limit on the low wavenumber side. Less than is more preferable.

(Symmetry of peak)
The symmetry S of the peak in the transmission spectrum can be calculated by the following procedure. That is, similarly to the edge steepness G, the transmission spectrum of the main surface 3a or the main surface 3b of the polymer photonic crystal 3 is measured, and the wavelength dependency of the transmittance is measured. As for the peak symmetry S, the same value can be calculated regardless of whether the vertical axis uses the transmittance or the OD value of the spectrum. For example, FIG. 4 is a drawing showing a transmission spectrum for explaining a method of calculating the symmetry of the peak, the vertical axis shows the OD value, and the horizontal axis shows the wavelength (nm).

Next, a perpendicular C is drawn with respect to the horizontal axis from the peak top of the wavelength peak of the transmission spectrum. Subsequently, a position Pa on the high wavelength side having an OD value 1/10 of the OD value of the peak top and a position Pb on the low wavelength side are specified on the transmission spectrum, and the shortest distance Wa between the perpendicular C and the position Pa is , And the shortest distance Wb between the perpendicular C and the position Pb. And symmetry S is computed from a following formula (5).

  The symmetry S is preferably 0.5 to 2.0, more preferably 0.8 to 1.5, and still more preferably 1.0 to 1.2. When the symmetry S is 1.0, the peak is symmetrical with respect to the perpendicular C. When the symmetry S is more than 2.0 or less than 0.5, the distribution of the structural period d is widened, and the transmission characteristics tend to be lowered due to a decrease in the degree of orientation.

  Polymeric photonic crystal 3 starts photopolymerization of a composition containing a block copolymer and a photopolymerization initiator, which will be described later, as a constituent component other than the block copolymer as a monomer component. It contains a photocurable resin (polymer compound) obtained by photopolymerization in the presence of an agent. The photopolymerizable monomer is preferably at least one selected from the group consisting of acrylates and methacrylates. The photopolymerizable monomer may be either a monofunctional monomer or a polyfunctional monomer. For example, carboxyethyl acrylate, isobornyl acrylate, octyl acrylate, lauryl acrylate, stearyl acrylate, nonylphenoxy polyethylene glycol acrylate, dicyclopentenyl acrylate , Monofunctional monomers such as dicyclopentenyloxyethyl acrylate, dicyclopentanyl acrylate, benzyl acrylate, phenoxyethyl acrylate, dicyclopentenyloxyethyl methacrylate, dicyclopentanyl methacrylate, benzyl methacrylate, octyl methacrylate, diethylene glycol acrylate, 1, 4-butanediol diacrylate, 1,6-hexanediol Acrylate, 1,9-nonanediol diacrylate, polypropylene glycol diacrylate, EO-modified bisphenol A diacrylate, dicyclopentanyl diacrylate, neopentyl glycol-modified trimethylolpropane diacrylate, 4,4'-diacryloyloxystilbene Diethylene glycol methacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol methacrylate, 1,9-nonanediol dimethacrylate, dicyclopentanyl dimethacrylate, neopentyl glycol dimethacrylate, EO-modified bisphenol A dimethacrylate, Tris (2-acryloyloxyethyl) isocyanurate, caprolactone-modified dipentaerythritol hexaacrylate, etc. Functional monomers are applicable. The photopolymerizable monomer is preferably a polyfunctional monomer. For example, dicyclopentanyl acrylate, neopentyl glycol-modified trimethylolpropane diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol acrylate, 1, More preferred are 9-nonanediol diacrylate, caprolactone-modified dipentaerythritol hexaacrylate, and the like. The said photopolymerizable monomer may be used independently, and may mix and use 2 or more types. The content of the photocurable resin is preferably 40 to 90% by mass based on the total mass of the polymer photonic crystal 3.

  The polymer photonic crystal 3 may contain other components such as a plasticizer. Examples of the plasticizer include at least one selected from phthalic acid esters such as dioctyl phthalate, adipic acid esters, phosphoric acid esters, trimellitic acid esters, citric acid esters, epoxy compounds, and polyesters. When the polymer photonic crystal 3 contains these plasticizers, the regularity of the microphase separation structure can be improved. The content of the plasticizer is preferably 5 to 50% by mass based on the total mass of the polymer photonic crystal 3.

  The lower limit value of the thickness of the polymer photonic crystal 3 is preferably 0.01 mm or more, more preferably 0.05 mm or more from the viewpoint that the orientation control can be performed more satisfactorily and further excellent optical characteristics can be obtained. Preferably, 0.10 mm or more is more preferable. The upper limit value of the thickness of the polymer photonic crystal 3 is preferably 1.00 mm or less, more preferably 0.80 mm or less, from the viewpoint that the orientation control can be performed more satisfactorily and further excellent optical characteristics can be obtained. Preferably, it is 0.60 mm or less.

  In the optical element 1 according to the present embodiment, the polymer photonic crystal 3 has the microphase separation structure 5 including the lamellar microdomains 7a and 7b, and thus depends on the orientation state of the microdomains 7a and 7b. Optical characteristics (for example, polarized light transmission characteristics) can be expressed. In the optical element 1 according to this embodiment, each of the lamellar microdomains 7a and 7b is oriented substantially parallel to the main surface 3a and the main surface 3b. As a result, the optical element 1 according to the present embodiment has optical characteristics as compared with an optical element using a conventional photonic crystal including a region in which microdomains are not oriented substantially parallel to the main surface of the crystal. Can be improved.

(Optical element manufacturing method)
The manufacturing method of the optical element 1 according to the present embodiment includes, for example, a solution preparation step, an orientation imparting step (first step), an annealing step, and a photopolymerization step (second step) in this order.

  In the solution preparation step, first, the above-described block copolymer having a polymer chain is polymerized. Examples of the polymerization method of the block copolymer capable of forming lamellar microdomains include living anionic polymerization.

  Next, the block copolymer and the photopolymerization initiator are dissolved in the soluble photopolymerizable monomer, and the block copolymer, the photopolymerization initiator, the photopolymerizable monomer, A polymer solution containing is prepared. The polymer solution can contain other components such as the plasticizer. At the stage of preparing such a polymer solution, the block copolymer forms a microphase separation structure in which the orientation is not controlled.

  The content of the block copolymer in the polymer solution does not need to be heated in order to reduce the viscosity in the production process, and is based on the total mass of the polymer solution from the viewpoint of making the polymer solution low in viscosity at room temperature and having fluidity. Is preferably 3 to 30% by mass, more preferably 5 to 20% by mass, and even more preferably 7 to 15% by mass. When the content of the block copolymer is less than 3% by mass, the segregation force when forming the microphase separation structure tends to decrease, and the regularity of the microphase separation structure tends to decrease. When the content of the block copolymer exceeds 30% by mass, the segregation force increases, but the viscosity increases, so that the orientation control by applying the flow field tends to be difficult.

  The photopolymerization initiator is a polymerization initiator that can be activated by irradiation with actinic rays. As a photopolymerization initiator, molecules are cleaved by irradiation with actinic rays to form radicals, causing a radical polymerization reaction with a photopolymerizable polymer or monomer, thereby increasing the molecular weight (crosslinking) of the material and proceeding to gelation. The radical type photoinitiator to be made to be mentioned. Examples of the photopolymerization initiator include benzyl dimethyl ketal, α-hydroxyalkylphenone, α-aminoalkylphenone and the like. More specific examples of the photopolymerization initiator include IRGACURE 651 (manufactured by Ciba Specialty Chemicals). These photopolymerization initiators may be used alone or in combination of two or more. The content of the photopolymerization initiator is preferably 0.05 to 0.5% by mass based on the total mass of the photopolymerizable monomer.

  Next, the orientation imparting step will be described with reference to FIG. First, a plate-like member (first member) 30 having flat main surfaces 30a and 30b facing each other substantially parallel to each other, and a plate-like member (second member) having flat main surfaces 40a and 40b facing each other substantially parallel to each other. 40) is prepared. The plate-like members 30 and 40 have, for example, a circular shape and are made of, for example, quartz glass. As for the diameter of the plate-shaped members 30 and 40, 20-100 mm is preferable, for example. The thickness of the plate-like members 30 and 40 is preferably, for example, 0.5 to 10 mm. The shapes, constituent materials, and sizes of the plate-like members 30 and 40 may be the same or different from each other.

  Subsequently, an annular (ring-shaped) spacer 50 having a circular opening 50 a is disposed on the main surface 30 a of the plate-like member 30. Spacer 50 is preferably arranged such that the center of opening 50a faces the center of main surface 30a. The outer diameter of the spacer 50 is, for example, 80 mm, and the thickness of the spacer 50 is adjusted according to the thickness of the film to be produced.

  Next, after the polymer solution 60 is developed in the opening 50a, the plate-like member 40 is disposed on the polymer solution 60 so that the main surface 30a and the main surface 40a face each other substantially in parallel. Accordingly, the polymer solution 60 is held between the plate-like member 30 and the plate-like member 40 in a state where the polymer solution 60 is in contact with the main surface 30a and the main surface 40a. After placing the plate member 30 and the plate member 40 so that the main surface 30a and the main surface 40a are substantially parallel to each other, the polymer solution 60 is injected between the main surface 30a and the main surface 40a. May be.

  The thickness of the polymer solution 60 is preferably 0.01 mm or more, more preferably 0.05 mm or more, and more preferably 0.10 mm or more from the viewpoint of enabling better control of the orientation and obtaining further excellent optical properties. Is more preferable. Further, the thickness of the polymer solution 60 is preferably 1.00 mm or less, more preferably 0.80 mm or less, from the viewpoint that the orientation control can be performed more satisfactorily and further excellent optical characteristics can be obtained. More preferably, it is 60 mm or less.

  Subsequently, with the polymer solution 60 interposed between the main surface 30a and the main surface 40a, the plate-like member 30 and the plate-like member 40 in a plurality of directions substantially parallel to at least one of the main surface 30a or the main surface 40a. Are moved relative to the polymer solution 60 in different directions, and a random shear flow field substantially parallel to at least one of the main surface 30a or the main surface 40a is applied to the polymer solution 60. For example, as shown in FIG. 5, the plate-like member 30 and the plate-like member 40 are rotationally moved while being vibrated (reciprocating) substantially parallel to the main surfaces 30a, 40a.

  The plate-like member 30 and the plate-like member 40 are preferably simply vibrated in the opposite directions at the same frequency. For example, when the plate-like member 30 moves in the direction D1, the plate-like member 40 is referred to as the direction D1. Move in the opposite direction D2. The plate-like member 30 and the plate-like member 40 are preferably rotated in the opposite directions at the same rotational speed. For example, the plate-like member 30 is based on the axis A1 passing through the center point P1 of the main surface 30b. Is rotated concentrically in the direction R1, and the plate member 40 is rotated concentrically in the direction R2 opposite to the direction R1 with reference to the axis A2 passing through the center point P2 of the main surface 40b.

  The polymer solution 60 includes a shear flow field generated by the vibration motion of the plate members 30 and 40 and a shear flow field generated by the rotation motion of the plate members 30 and 40 in the in-plane direction substantially parallel to the main surfaces 30a and 40a. Is applied. Thereby, a shear flow field is applied to the polymer solution 60 in a plurality of directions in a plane substantially parallel to the main surfaces 30a and 40a, that is, a random shear flow field is applied. As a result, a microphase separation structure is formed in which each of the lamellar microdomains 7a and 7b in the polymer solution 60 is oriented substantially parallel to the main surfaces 30a and 40a.

  The random shear flow field is applied not only in the vicinity of the main surfaces 30 a and 40 a in the polymer solution 60 but also in the central region in the thickness direction of the polymer solution 60. The magnitude of the random flow field applied in the polymer solution 60 can be appropriately adjusted according to the movement speed and movement time of the plate-like members 30 and 40.

  Examples of a method for applying a random shear flow field to the polymer solution 60 include the method shown in FIGS. 6 and 7 in addition to the method shown in FIG. 6 and 7 illustrate a method of causing the plate-like member 40 to vibrate or steadily move in a plane substantially parallel to the main surface 40a. Here, “steady motion” means a motion in which a predetermined motion is repeatedly performed at a constant speed, and examples thereof include a rotational motion, a turning motion, and a planetary motion, which will be described later. 6 and 7, illustration of members other than the plate-like member 40 is omitted for convenience. Reference numeral 70 in FIG. 7 is described to clearly indicate the presence or absence of the rotational motion of the plate-like member 40, and is not actually displayed.

Examples of a method for applying a random shear flow field to the polymer solution 60 include the following methods (a) to (e).
(A) “Vibrating motion in a plurality of directions without rotational motion (spinning motion)”: A method in which the plate-like member 40 is vibrated in one direction and then vibrated in the other direction (FIG. 6A).
(B) “Vibrating motion with rotational motion (spinning motion)”: A method of vibrating the plate member 40 in a uniaxial direction while rotating the plate member 40 with reference to the axis A2 passing through the center point P2 of the main surface 40b (FIG. 5, FIG. 6 (b)).
(C) A method of vibrating the plate member 40 in a uniaxial direction before or after rotating the plate-like member 40 with reference to the axis A2 passing through the center point P2 of the main surface 40b.
(D) “Rotating motion”: A method of rotating the plate-like member 40 around a reference axis passing through a reference point P3 different from the center point P2 of the main surface 40b and perpendicular to the main surface 40b.
(E) “Planet motion”: The plate member 40 is rotated around the reference axis passing through the reference point P3 while rotating the plate member 40 with respect to the axis A2 passing through the center point P2 of the main surface 40b. How to exercise.

  As a method for applying the random shear flow field, the shear flow field may be applied simultaneously to the polymer solution in a plurality of directions, or the shear flow field may be applied to the polymer solution in a plurality of directions. The methods (b), (d), and (e) are mentioned as methods for simultaneously applying shear flow fields in a plurality of directions. Examples of the method of applying shear flow fields in multiple directions in multiple stages include the above methods (a) and (c). A random shear flow field cannot be applied when a rotary motion or a uniaxial vibration motion is performed independently, but by performing each motion in multiple stages as in method (c), A random shear flow field can be applied. In the swivel motion, the application direction of the shear flow field changes with time as the plate-like members 30 and 40 move, so the shear flow field is applied in a random direction.

  In FIGS. 7A and 7B, the plate-like member 40 is turned around the reference axis located outside the plate-like member 40. However, a reference point is selected from the main surface 40b and the reference point is selected. The plate-like member 40 may be swung around a reference axis that passes through and is perpendicular to the main surface 40b. In FIG. 7B, the rotational direction of the rotational motion and the rotational direction of the rotational motion are preferably opposite to each other. In addition to the above methods (a) to (e), vibration motion, rotational motion, swivel motion, and planetary motion may be further performed.

  The plate members 30 and 40 are moved so that the directions of movement are opposite to each other, and shear flow fields applied to the polymer solution 60 from the plate members 30 and 40 are applied in opposite directions. preferable. Since the magnitude of the random shear flow field applied to the polymer solution 60 from each of the plate members 30 and 40 is substantially the same and the orientation degree of the microdomains tends to be uniform, the method of moving the plate members 30 and 40 The movement conditions are preferably substantially the same except for the movement direction.

The motion method and motion conditions of the plate-like members 30 and 40 are appropriately selected according to the thickness of the polymer solution 60. When the thickness of the polymer solution 60 is 0.01 to 1.00 mm, The average orientation degree P, the edge steepness G, and the peak symmetry S are preferably adjusted as follows from the viewpoint of being easily adjusted to the preferable ranges. Frequency of oscillatory motion is preferably 0.1~5s ^-1, 0.5~2s ^-1 are more preferred. The rotational speed of the rotational motion is preferably 0.1 to 50 rpm, and more preferably 1 to 25 rpm. 1-100 rpm is preferable and, as for the rotation speed of a turning motion, 2-60 rpm is more preferable. The temperature of the polymer solution 60 is preferably room temperature (25 ° C.), and the flow field application time is preferably 5 to 120 minutes.

  In the annealing step, the polymer solution having the microphase separation structure in which the orientation of the microdomain is controlled in the orientation imparting step is annealed to improve the regularity of the microphase separation structure. The annealing temperature is preferably 15 to 100 ° C.

  In the photopolymerization step, the photopolymerizable monomer in the polymer solution is polymerized by irradiating the polymer solution with active light (for example, ultraviolet rays). Thereby, the micro phase separation structure can be fixed by a simple method while maintaining the micro phase separation structure formed in the orientation imparting step.

  As described above, as shown in FIG. 1, a lamellar microdomain 7a having a polymer chain 9a as a main component and a lamellar microdomain 7b having a polymer chain 9b as a main component are alternately laminated. The optical element 1 including the polymer photonic crystal 3 having 5 can be obtained.

  In the manufacturing method of the optical element 1 according to the present embodiment, in the orientation imparting step, a block copolymer, a photopolymerization initiator, and a photopolymerizable monomer are provided between the main surface 30a and the main surface 40a facing each other. With the polymer solution 60 contained, the plate-like members 30 and 40 are moved relative to the polymer solution 60 in different directions substantially parallel to the main surface 30a and the main surface 40a to generate a random shear flow field. Apply to polymer solution 60. Thereby, the orientation of each of the lamellar microdomains in the microphase-separated structure 5 is controlled substantially parallel to the main surface 30a and the main surface 40a.

  Then, in the photopolymerization step, the photopolymerizable monomer in the polymer solution 60 is polymerized to fix the microphase separation structure 5 while maintaining the orientation state of the microphase separation structure 5 obtained in the orientation imparting step. Thus, the polymer photonic crystal 3 can be obtained. In the method for manufacturing the optical element 1 according to the present embodiment, the orientation of each of the microdomains 7a and 7b is controlled to be substantially parallel to the main surface 30a and the main surface 40a. Optical characteristics can be improved as compared with a photonic crystal optical element using a conventional block copolymer including a region that is not sufficiently oriented substantially in parallel.

  In the method for manufacturing the optical element 1 according to this embodiment, a random shear flow field is applied to the polymer solution 60, and the block copolymer self-assembles to form the microphase separation structure 5. Thereby, compared with the case where a photonic crystal is formed by top-down processing, the manufacturing cost of a photonic crystal can be reduced significantly.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, examples of the optical element include a laser resonator in addition to a Raman spectroscope, a notch filter for use in a fluorescence microscope, and a dichroic mirror.

  In the above-described embodiment, the openings 50a of the plate-like members 30 and 40 and the spacer 50 are circular, but are not limited to this, and may be rectangular, for example.

  In the above-described embodiment, the two plate members 30 and 40 facing each other are used, but a random shear flow field may be applied to the polymer solution 60 using three or more plate members. For example, two plate members may be disposed on the polymer solution, and each plate member may be moved to apply a random shear flow field to the polymer solution 60.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to these.

<Example 1>
(Film production)
First, as a block copolymer, polystyrene-b-poly (tert-butyl methacrylate) (PS-bP (t-BMA)) (weight average molecular weight 1.0 × 10 ⁶ [g / mol], PS: P (T-BMA) = 38: 62 [vol%]) was synthesized by living anionic polymerization under vacuum. Next, the block copolymer is mixed into a mixed solvent containing 1,6-bis (acryloyloxy) hexane as a photopolymerizable monomer and dioctyl phthalate as a plasticizer in a mass ratio of 70:30. It was dissolved so that it might become 15 mass% on the basis of total mass, and the mixture was obtained. In addition, IRGACURE651 (manufactured by Ciba Specialty Chemicals) was added to the mixture as a photopolymerization initiator so that the content was 0.3% by mass relative to the content of 1,6-bis (acryloyloxy) hexane. A solution was obtained.

  A ring-shaped spacer having a thickness of 0.3 mm and an opening inner diameter of 40 mm was placed on the main surface of a circular quartz glass plate (diameter 50 mm, thickness 1.0 mm), and then the polymer solution was dropped into the spacer opening. . Subsequently, a circular quartz glass plate similar to the above was placed on the spacer, and the polymer solution was sandwiched between the quartz glass plates up and down to be developed into a circular film shape.

  Next, each of the two quartz glass plates sandwiching the polymer solution is randomly moved in different directions in a plane parallel to the main surface, and a random shear flow field is applied to the polymer solution (room temperature: 25 ° C.) to thereby form a microphase. The lamellar microdomains of the separated structure were oriented. The two quartz glass plates were moved relative to the polymer solution by swirling motions in opposite directions (the above method (d) (FIG. 7A)). The rotational speed of the rotating motion was 10 rpm, and the application time of the flow field was 5 minutes.

After applying the shear flow field, the regularity of the microphase separation structure was improved by annealing at room temperature for 24 hours so as not to add excessive flow. Thereafter, the polymer solution was cured by irradiating the polymer solution with ultraviolet rays for 5 minutes (1820 μW / cm ² ) to obtain a polymer photonic crystal film in which microdomains were oriented. The thickness of the polymer photonic crystal film was 0.3 mm.

<Comparative Example 1>
(Film production)
First, after a polymer solution was obtained by the same method as in Example 1, the polymer solution was sandwiched between quartz glass plates by the same method as in Example 1 and developed into a circular film shape.

  Next, two quartz glass plates sandwiching the polymer solution are rotated concentrically in opposite directions, and a uniaxial shear flow field is applied to the polymer solution (room temperature: 25 ° C.) to form a microphase separation structure. Lamellar microdomains were oriented. The rotational speed of the rotary motion was 5 rpm, and the application time of the flow field was 5 minutes.

After applying the shear flow field, the regularity of the microphase separation structure was improved by annealing at room temperature for 24 hours so as not to add excessive flow. Thereafter, the polymer solution was cured by irradiating the polymer solution with ultraviolet rays for 5 minutes (1820 μW / cm ² ) to obtain a polymer photonic crystal film in which microdomains were oriented. The thickness of the polymer photonic crystal film was 0.3 mm.

(TEM observation)
The polymer photonic crystal films of Example 1 and Comparative Example 1 were cut in the thickness direction, and the film cross section was observed with a transmission electron microscope (TEM). FIG. 8 is a TEM photograph of the polymer photonic crystal film of Example 1. FIG. 9 is a TEM photograph of the polymer photonic crystal film of Comparative Example 1, and FIG. 9B is an enlarged view of region D in FIG. 9A.

  As shown in FIGS. 8 and 9, it was confirmed that in both Example 1 and Comparative Example 1, lamellar microdomains were formed. It was confirmed that the polymer photonic crystal film of Example 1 in which orientation control was performed by applying a random shear flow field had no defects and had a periodic structure. On the other hand, as shown in FIG. 9, in the polymer photonic crystal film of Comparative Example 1 in which only the rotational shear flow field was applied to control the orientation, a plurality of defects were observed, and it was confirmed that the periodic structure was disordered. .

(Orientation evaluation)
Using the polymer photonic crystal film of Example 1 and Comparative Example 1, the degree of orientation of the micro domain in the micro phase separation structure (refractive index periodic structure) was measured by small angle X-ray scattering measurement of the large synchrotron radiation facility SPring8 beam line 19B2. evaluated. A scattering pattern was measured by making X-rays incident on a cross section of the film cut in the thickness direction.

  FIG. 10 is a drawing showing a two-dimensional scattering pattern of a polymer photonic crystal film. FIG. 11 is a drawing showing the azimuth dependence of scattering intensity in a polymer photonic crystal film. In FIG. 11, the azimuth angle of 0 ° corresponds to the direction perpendicular to the main surface of the film (the meridian direction in FIG. 10). 10 (a) and 11 (a) are measurement results of the polymer photonic crystal film of Example 1. FIG. FIG. 10B and FIG. 11B are measurement results of the polymer photonic crystal film of Comparative Example 1. As shown in FIG. 10, it was confirmed that the polymer photonic crystal film of Example 1 was less disturbed in the azimuth direction than the polymer photonic crystal film of Comparative Example 1.

  With respect to the polymer photonic crystal film of Example 1, the average orientation degree P was calculated from the above formula (1) from the azimuth angle dependency of the scattering intensity shown in FIG. It was confirmed that the degree of orientation of lamellar microdomains with respect to the main surface of the film was excellent.

  With respect to the polymer photonic crystal film of Comparative Example 1, when the average orientation degree P was calculated from the above formula (1) based on the azimuth angle μ dependence of the scattering intensity I (μ) shown in FIG. 86. It was confirmed that the degree of orientation of lamellar microdomains with respect to the main surface of the film was not sufficient.

(Optical property evaluation)
The transmission spectra of the polymer photonic crystal films of Example 1 and Comparative Example 1 were measured to evaluate the polarization transmission characteristics. A spectrophotometer U-3500 (manufactured by Hitachi, Ltd.) was used for measurement of the transmission spectrum.

  The obtained transmission spectrum is shown in FIG. In FIG. 12, the solid line E is the transmission spectrum of Example 1, and the broken line F is the transmission spectrum of Comparative Example 1. In the polymer photonic crystal film of Example 1, it was confirmed that a steep peak was obtained on both the high wavelength side and the low wavelength side as compared with the polymer photonic crystal film of Comparative Example 1. . In the polymer photonic crystal film of Example 1, it was confirmed that the microdomains were uniformly oriented.

  Based on the above formulas (3) and (5), the peak edge steepness and symmetry in the transmission spectrum of Example 1 were calculated to be 1.1% and 1.1, respectively. In Example 1, it was confirmed that a polymer photonic crystal film having excellent transmission characteristics with high wavelength selectivity was produced.

  Similarly, the peak edge steepness and symmetry in the transmission spectrum of Comparative Example 1 were calculated to be 2.8% and 2.5, respectively. In Comparative Example 1 in which only the rotational shear flow field was applied, it was confirmed that a polymer photonic crystal film having sufficient transmission characteristics was not produced.

  DESCRIPTION OF SYMBOLS 1 ... Optical element, 3 ... Polymer photonic crystal, 3a ... Main surface (1st main surface), 3b ... Main surface (2nd main surface), 5 ... Micro phase-separation structure, 7a, 7b ... Micro domain , 30 ... plate-like member (first member), 40 ... plate-like member (second member), 30a, 40a ... main surface, 60 ... polymer solution.

Claims (10)

With a high molecular photonic crystal film that have a first major surface and a second principal surface opposed to each other,
The polymer photonic crystal film contains a block copolymer and has a microphase separation structure including lamellar microdomains,
Each of the micro domains, are oriented substantially parallel to and against the first major surface and said second major surface,
Average orientation degree P of the microdomains which are defined by the following formula (1) is Ru der 0.92 or more, optical elements.

(In the formula, μ represents an azimuth angle in small-angle X-ray scattering measurement, and <cos ² μ> is defined by the following formula (2).)

(In the formula, I (μ) represents the scattering intensity at the azimuth angle μ.) Wherein the first major surface and substantially perpendicular plurality of cross-sectional to said second major surface, the difference between the average orientation degree P falls within 0 to 0.05, the optical element according to claim 1. Transmission spectrum of the polymer photonic crystal film has between a wavelength band and the stop band and the pass band is the slope G is less than 2.0% defined by the following formula (3), according to claim 1 or 2 An optical element according to 1.

(Wherein, λ ₅₀ represents a wavelength (nm) showing a transmittance of 50% in the wavelength band, and λ _B represents a wavelength (nm) at the boundary between the stop band and the wavelength band.) The weight average molecular weight of the block copolymer is 8.0 × 10 ⁵ or more, the optical element according to any one of claims 1-3. The polymer photonic crystal film further contains a polymer compound obtained by polymerizing a composition containing at least one photopolymerizable monomer selected from the group consisting of acrylates and methacrylates of claim 1-4 The optical element as described in any one. The polymer photonic crystal film further contains at least one selected from the group consisting of phthalic acid ester, adipic acid ester, phosphoric acid ester, trimellitic acid ester, citric acid ester, epoxy compound and polyester. The optical element according to any one of 1 to 5 . A block copolymer, a photopolymerization initiator, and a photopolymerizable monomer in which the block copolymer and the photopolymerization initiator are soluble between the main surface of the first member and the main surface of the second member facing each other. while interposing a solution containing the door, the first member and the main surface and the second member wherein the first member and the second member different directions substantially parallel to each other on the main surface of the solution A first step of applying a random shear flow field to the solution, relative to the solution;
After the first step, the solution is irradiated with light to polymerize the photopolymerizable monomer, lamellar microdomains are for the main face of the main surface and the second member of the first member A second step of obtaining a polymer photonic crystal film oriented substantially in parallel,
The method of moving the first member and the second member relative to the solution includes a method of oscillating in a uniaxial direction and then oscillating in a different direction, a method of oscillating in a uniaxial direction while rotating, a uniaxial A method of manufacturing an optical element, which is a method of rotationally moving after vibrating in a direction, a method of rotating in a uniaxial direction after rotating, a method of rotating, or a method of planetary motion. The method for producing an optical element according to claim 7 , wherein the block copolymer has a weight average molecular weight of 8.0 × 10 ⁵ or more. The method for producing an optical element according to claim 7 or 8 , wherein the photopolymerizable monomer is at least one selected from the group consisting of acrylate and methacrylate. Said solution of phthalic acid esters, adipic acid esters, phosphoric acid esters, trimellitic acid esters, citric acid esters, further contains at least one selected from the group consisting of an epoxy compound and polyester, any claim 7-9 A method for producing an optical element according to claim 1.